DSA
Master the patterns
Search the bank, then filter by difficulty, pattern, data structure, or algorithm. Each problem includes approaches, solutions, and walkthroughs.
Active·2,723
Easy·667
Medium·1,394
Hard·662
Patterns
Recognize the move
Filter the bank by pattern — each card links into the problem index.
Problem index
Browse problems
Search by title, then refine with facets. Sorted by problem ID.
Difficulty
Facets
20 of 28 matching · 2723 totalSort: id ↑
No.ProblemDifficulty
- 0003Longest Substring Without Repeating CharactersMed
- 0005Longest Palindromic SubstringMed
- 0010Regular Expression MatchingHard
- 0022Generate ParenthesesMed
- 0025Reverse Nodes in k-GroupHard
- 0032Longest Valid ParenthesesHard
- 0034Find First and Last Position of Element in Sorted ArrayMed
- 0041First Missing PositiveHard
- 0042Trapping Rain WaterHard
- 0045Jump Game IIMed
- 0055Jump GameMed
- 0056Merge IntervalsMed
- 0072Edit DistanceMed
- 0076Minimum Window SubstringHard
- 0079Word SearchMed
- 0155Min StackMed
- 0169Majority ElementEasy
- 0196Implement Trie (Prefix Tree)Med
- 0226Product of Array Except SelfMed
- 0227Sliding Window MaximumHard
Showing 20 of 28